Method and apparatus for loading flash lamps with filamentary combustible material



Feb. 11, 1964 R. M. ANDERSON ETAL 3,120,694

METHOD AND APPARATUS FOR LOADING F LASH LAMPS WITH FILAMENTARY COMBUSTIBLE MATERIAL Filed Aug. 10, 1960 I'm/an hors: Robevd: M. Andevson Louis A. Demchock, Jr.

s wg T he iT" drorneg United States Patent pany, a corporation of New York Filed Aug. 10, 1960, Ser. No. 48,606 3 Claims. (Cl. 29-2511) Our invention relates, in general, to the manufacture of flash lamps of the type employing, as the light-producing element thereof, a quantity of readily combustible filamentary material in the form of a multiplicity of relatively short lengths of fine wire, or finely cut strands of metal foil such as that commonly referred to as shredded foil. More particularly, our invention relates to a method and apparatus for introducing such type filamentary combustible material in a crinkled or rumpled condition into, and distributing it uniformly within, the bulb of the flash lamp.

The filamentary combustible material most commonly employed at present in flash lamps as the light-producing element thereof is that produced by the method and ap paratus disclosed in US. Patent 2,297,368, Rippl et al., dated September 29, 1942, and consisting of fine cut strands of metal foil commonly known as shredded foil. As formed, such cut strands are essentially of linear or uncrurnpled form.

To obtain the most elfective combustion of the combustible material and thus the best light-producing performance from the finished flash lamp, it is desirable that the individual foil strands constituting the charge of combustible material in each flash lamp be distributed as uniformly as possible within the lamp bulb. This can best be assured by forming and disposing the individual foil strands in a crumpled or rumpled condition within the lamp bulb. However, with the methods most commonly employed at present for introducing such shredded foil combustible material into lamp bulbs wherein the material is transported into the bulb by a stream of air flowing through a feed tube either extending into the bulb or terminating directly opposite and aligned with the opening into the bulb, as disclosed and claimed for instance in US. Patents 2,347,046, Geiger et al., dated April 18, 1944, 2,722,355, Anderson, dated November 1, 1955, and 2,773,520, Dell et al., dated December ll, 1956, such a crumpled or rumpled condition of the shredded foil strands in the lamp bulb, and resulting uniform distribution of the foil strands therewithin, is not obtained in the case of certain types of flash lamps. This is particularly true, for example, in the case of extremely small size flash lamps such as that commercially known as the AGl lamp where, because of the very small interior space thereof and, especially in the case or" the AGl lamp, because of the particular interior configuration of the bulb space and the presence of the lamp ignition mount therein at the time of introduction of the combustible material thereinto, the individual strands of the shredded foil are prevented from being swirled and fluffed about the interior space of the bulb by the recurrent flow of the foil-trans porting air therein and thus becoming crumpled or rumpled to thereby assume a uniformly distributed condition in the bulb. Instead, the individual foil strands, in such extremely small size flash lamps, are usually left in a twisted-together or rope-like condition disposed in what may be described as a doughnut shape about the interior wall of the lamp bulb.

It is an object of our invention, therefore, to provide a novel method and apparatus for automatically introducing short and substantially linear shaped strands of filamentary combustible material into a flash lamp bulb which will assure in substantially every case the formation of a crumpled and uniformly distributed arrangement of the combustible material in the bulb, regardless of the size or shape thereof.

Another object of our invention is to provide a method and apparatus for pneumatically transporting short and substantially linear shaped strands of filamentary combustible material and introducing them in a thoroughly crumpled condition into a flash lamp bulb so as to form in every case a uniformly distributed filling of such material in the bulb.

Briefly stated, in accordance with one aspect of our invention, substantially linear shaped strands of combustible filamentary material for a flash lamp bulb are introduced and uniformly distributed in a crumpled condition therein by entraining the strands in a stream of air within a feed passageway which is provided with an intermediate enlarged chamber portion against the wall of which the strands are forcefully impinged, and within which chamber the strands are momentarily trapped and tossed about by the varying air currents therein, to effect the ciumpling of the strands prior to their continued passage through the remainder of the feed passageway and into the lamp bulb.

Further objects and advantages of our invention will appear from the following detailed description of a species thereof and from the accompanying drawing.

In the drawing, the single figure thereof is a diagrammatic illustration showing the method of manufacturing filamentary combustible material for a flash lamp and the method and apparatus comprising our invention for introducing such combustible material into the bulb for a flash lamp.

Referring to the drawing, the apparatus there shown for forming the strands of filamentary combustible material for a flash lamp, and introducing such material into the bulb of the lamp, is in general the same as that described and claimed in US. Patent 2,347,046, Geiger et al., dated April 18, 1944, except for the structure of the strand-transporting passageway 1 thereof and the action of such passageway on the foil strands as they pass therethrough. A detailed description of the entire apparatus and its operation is unnecessary to a full understanding of the present invention but may be had, if desired, by reference to the above-mentioned Geiger et al. patent.

In general, however, the apparatus comprises a cutting mechanism 2 for slicing extremely fine ribbons or shreds from an advancing sheet 3 of metal foil such as zirconium or aluminum foil, for instance, having a thickness of from .0005 to .001 inch and a suitable uniform width which may range, for example, from 4 to 8 inches or so. The metal foil sheet 3 is supplied from a roll 4 thereof rotatably mounted on the apparatus, and it is advanced at a uniform rate by cooperating feed rolls 5 and 6, between which the sheet 3 passes, to the cutting means of the apparatus which comprises a bed knife 7 and a cooperating rotatable cutter 8. The speed of advance movement of the foil sheet 3 by the feed rolls 5, 6 and the rotational speed of the rotary cutter 8 are so proportioned as to cut strips or ribbons from the sheet 3 of a width of the order of .0005 to .001 of an inch. In the operation of the apparatus, the cutting of the foil sheet 3 by the knives 7, 3 is interrupted for a short time at regular intervals, after the required number of strips constituting the desired charge for a single lamp have been cut, by a stoppage of the rotational movement of the feed rolls 5, 6 which thus interrupts the advance of the foil sheet 3 to the cutters 7, 8.

As the individual foil strands or strips 51* are cut and drop from the cutter knives '7, 8, they are picked up by a suction nozzle at the entrance end of a feed tube 11 forming a part of the passageway 1 for transporting the foil strands into the lamp bulb, the nozzle 10 being located directly beneath and contiguous to the cutting edge of the bed knife 7. The strips 9 of filamentary strand material are drawn through the feed tube 11 of the passageway 1 by a suction of air therethrough and are discharged from its delivery end 12 which extends upwardly and in a straight path into the lower end of the hollow interior 13 of a suction head or enclosure 14 with which the feed tube 11 has an airtight connection. The hollow interior 13 of the suction head or enclosure 14 is connected to a suitable exhaust means or source of vacuum (not shown), such as an exhaust pump, through outlet tube or pipe 15, and an electrically controlled solenoid valve (not shown) located in the said outlet pipe or vacuum line 15 operates to periodically interrupt the vacuum connection to the suction head 14 during the period when an alternate suction head (not shown), the exact duplicate of head 14, is in operation, it being understood that the apparatus is provided with two suction heads 14 for alternate operation, as disclosed in the said previously mentioned Geiger et al. Patent 2,347,046. For the purposes of the invention, the exhaust means employed to produce the suction in the feed tube 11 during the operation of the apparatus should be suflicient to transport the foil strands through the feed tube and deposit them in the bulb.

From the delivery end 12 of the feed tube 11, the foil shreds or strands 9 are delivered into the lamp bulb or container 16 to be filled with the strand material. The particular bulb 16 illustrated is of the extremely small size type employed for the aforementioned AGl type flash lamp and consisting of a short length of comparatively small diameter (e.g., /8 inch inside diameter) glass tubing into one end 17 of which a lamp mount 18 is sealed to thereby close off the said tube end, the other end 19 of the glass tube being left open. As shown, the glass bulb or tube 16 is supported for loading on the top end of the suction head 14, with its open neck end 19 extending downwardly into the opening in the upper end of the suction head and into the hollow interior 13 thereof in vertical alignment with the straight delivery end 12 of the feed tube 11. The bulb 15 seats vacuum-tight against a suitable annular rubber gasket 27 such as an O-ring bordering the opening in the upper end of the suction head 14. When thus seated against the gasket 27, the bulb 16 closes off the opening at the upper end of the suction head 14, as a result of which the withdrawal of air from the hollow interior 13 of the suction head by the exhaust means acts to create a suction in the feed tube 11 which then serves to draw the strips or strands of filamentary material through the feed tube 11 constituting the passageway 1 and into the bulb 16 seated in the suction head. The delivery end 12 of the feed tube 11 may either extend into the interior of the bulb 16 as shown, or it may terminate at a point outwardly of but adjacent to and aligned with the open end 19 of the bulb in the manner disclosed in the aforementioned Anderson Patent 2,722,355. In either case, however, the foil strands 9 are discharged from the open delivery end 12 of the feed tube 11 and deposited in the bulb or tube 16 by the stream of air flowing through the feed tube.

As cut by the cutting knives '7, S, the shredded foil strands 9 are essentially of straight or linear form. Upon being drawn into the feed tube 11 by the suction nozzle 10 at a point more or less near the center of their respective lengths, the foil strands 9 become doubled into a U or hairpin shape, in which form they are then ordinarily discharged into the bulb 16 in the case where the pneumatic foil-filling apparatus is essentially of the type heretofore customarily employed and embodying a foil transporting passageway 1 consisting of a substantially continuous length of feed tubing 11 extending from the picknozzle 10 to the delivery end 12 thereof. As a result, such U-shaped and therefore substantially linear or uncrumpled foil strands tend to form themselves, particularly in the case where the bulb to is of extremely small size such as that employed for the above-mentioned AGl flash lamp, into a twisted rope-like gathering thereof in the bulb extending around the inside wall thereof in the manner of a doughnut shape. The inserted charge of filamentary combustible material in such extremely small size bulbs thus is not arranged therein in the desired uniform manner such as to assure its most effective combustion and thus the maximum light production from the lamp when flashed.

To prevent the occurrence of any such twisted ropelilte arrangement of the strands of filamentary combustible material in the bulb 1+6, irrespective of the size or shape thereof, and to effect the introduction of the foil strands 9 into the bulb 16 in a thoroughly crumpled or crinkled condition instead so as to be substantially uniformly distributed therein in every case, the shredded foil transporting passageway 1 is provided, in accordance with the invention, with an intermediate enlarged chamber portion 29 located intermediate the entrance or nozzle end it) and the discharge end 12 of the feed tube or conduit 11, within which chamber the U-shape foil strands 9 are temporarily trapped during their passage through the passageway 1 and are tossed about by the various air currents occurring in the chamber during the operation of the loading device to thereby effect a thorough crinkling or rumpling of the foil strands prior to their continuing passage through the remainder of the feed conduit 11 and into the bulb 16. Such preliminary crinltling or crumpling of the foil strands 9 in the chamber 20 prior to their discharge into the bulb 16 then automatically assures the uniform distributing of the crumpled foil strands 9 about the interior space of the bulb as they leave the discharge end 12 of the feed conduit 11 and enter the bulb.

For the purposes of the invention, the foil strand crinkling chamber 20 may be of generally bowl shape as shown, and the supply portion 21 of the feed tube or conduit 11 leading from the strand pick-up nozzle 10 is connected in an air-tight manner into the chamber 29 as, for instance, by means of a rubber stopper or ring 22 fitting within the opening into the chamber, so as to extend straight into the chamber in a direction toward and more or less normal to the end wall 23 of the chamber, and with the open end 24 of the supply feed tube portion 21 disposed directly opposite and closely adjacent the said end wall 23 so as to asssure the forceful impingement of the foil strands 9 directly against the end wall 23 upon emergence from the open discharge end 24 of the supply feed tube portion 21. As shown, the end wall 23 of the foil strand curling chamber 20 preferably is made of a somewhat rounded form, and the supply feed tube portion 21 is made of an inside diameter (e.g., around /8 or so) considerably smaller than that heretofore employed for the feed tube 11 in order to impart the necessary increased velocity to the foil strands 9 as they pass through the feed tube to cause them to be forcefully impinged against the end wall 23 of the chamber 20 and thereby becoming crumpled or crinkled. In addition, the chamber 20 is made of a cross-sectional size or diameter considerably greater than that of the supply feed tube portion 21 in order to thereby reduce the velocity of the foil transporting air stream within the chamber to a sufficiently low degree to cause the foil strands 9 to be momentarily trapped within the chamber, and tossed about therein by the varying air currents in the chamber, so as to repeatedly strike against the wall thereof and thus be further crumpled or crinkled. For example, the chamber 29 may be formed with an inside diameter, transversely of the supply feed tube 21 extending thereinto, of around 1%" or so, where the feed tube portion 21 is formed with an inside diameter or" A5 or so.

The chamber 20 is provided with an outlet or discharge opening 25 in its side wall at a point removed from the region of the end wall 23 against which the foil strands 9 impinge as they emerge from the supply feed tube portion 21, through which outlet opening 25 the foil strands 9, which are now in a thoroughly crumpied or crinkled condition, then leave the chamber 2t) and continue on their passage through the remainder of the feed tube 11, through the outlet or sweep tube portion 26 thereof which is connected to the said outlet opening 25. Because of the curled or crumpled condition and therefore larger spacial size of the individual foil strands 9 as they leave the curling chamber 26, the sweep tube portion 26 of the feed conduit 11 is made of a size sufficiently large to prevent the clogging thereof by the curled or crumpled foil strands 9. To this end, the sweep or discharge portion 26 of the feed tube 11 may be made with an inside diameter of around A or so and converging slightly near its discharge end 12 to an inside diameter of around or so.

By virtue of the interposition, in accordance with our invention, of the foil strand crinkling chamber 29 in the feed passageway ll of the shredded foil filling apparatus, the individual foil strands are in a thoroughly crumpled or crinkled form at the time they are discharged from the discharge end 12 of the feed tube 11 and flung into the interior space of the bulb. As a result, the foil strands automatically arrange themselves in a substantially uniformly distributed manner, entirely free from twisted together rope-like gatherings thereof, within the interior of the bulb in every case, regardless of the size or shape of the bulb, such as then assures the most effective combustion of the combustible filling material in the hash lamp when flashed with resultant maximum light output therefrom.

Although a preferred embodiment of our invention has been disclosed, it will be understood that the invention is not to be limited to the specific construction and arrangement of parts shown, but that they may be widely modified within the spirit and scope of our invention as defined by the appended claims.

What we claim as new and desire to secure by Letters Patent of the United States:

1. The method of transporting fine strands of combustible material of substantially uncrumpled form, and discharging them in crumpled form into a flash lamp bulb having an opening thereinto, which comprises arranging the bulb with its said opening opposite and in vacuumtight communication with an open delivery end of a passageway, presenting the strands of combustible material to the open entrance end of such passageway, drawing air through said passageway and out of said bulb to create a suction in the passageway serving to carry the strands therethrough and discharge them into said bulb, and temporarily interrupting the movement of said strands before the strands are discharged from said passageway and crumpling them therein by releasing the strands into and impinging them directly against the wall of an enlarged chamber portion of said passageway.

2. Apparatus for transporting fine strands of combustible material of substantially uncrumpled form, and discharging them in crumpled form into a flash lamp bulb having an open end, comprising a hollow suction head provided with an opening thereinto and having an annular seat around said opening against which the bulb is adapted to seat to connect the open end thereof in vacuumtight communication with the hollow interior of the suction head, a feed conduit having an open discharge end extending into said suction head in a direction toward and in alignment with the said opening therein and terminating at its other end in a pick-up nozzle end, and means connecting the said suction head to a source of vacuum to exhaust the suction head and the bulb seated therein and withdraw the air in said feed conduit out the said discharge end thereof to thereby create a suction in said feed conduit serving to carry the strands therethrough and discharge them into the bulb, said feed conduit being provided with an enlarged chamber portion located intermediate its said nozzle and discharge ends and into which the portion of the feed conduit leading from the nozzle end thereof extends in a direction substantially normal to and terminating closely adjacent the Wall of the chamber for impinging the strands of combustible material forcefully against the said wall thereof and momentarily trapping the said strands within the chamber and tossing them about therein to effect a crumpling of the strands 3. Apparatus for loading a flash lamp bulb with strands of filamentary combustible material comprising a hollow suction head for supporting the bulb in a vacuum-tight manner therein with the opening of the bulb in communication with the hollow interior of the suction head, means connecting the suction head to a source of vacuum, an open-ended discharge feed tube connected in a vacuumtight manner with the suction head and extending thereinto in a direction toward and aligned with the opening of the bulb positioned in the suction head, a bowl-shaped chamber into the side wall of which said discharge feed tube is cormected, and an open-ended supply feed tube provided at one end with a strand pick-up nozzle and connected adjacent its other end in a vacuum-tight manner into the said chamber and extending straight thereinto in a direction substantially normal to and terminating closely adjacent the bowl-shaped end wall thereof.

References Cited in the file of this patent UNITED STATES PATENTS 2,115,423 Korver Apr. 26, 1938 2,347,046 Geiger Apr. 18, 1944 2,722,355 Anderson Nov. 1, 1955 2,759,646 White Aug. 21, 1956 2,772,763 Bennett et al. Dec. 4, 1956 2,773,520 Dell et al Dec. 11, 1956 

1. THE METHOD OF TRANSPORTING FINE STRAND OF COMBUSTIBLE MATERIAL OF SUBSTANTIALLY UNCRUMPLED FORM, AND DISCHARGING THEN IN CRUMPLED FORM INTO A FLASH LAMP BULB HAVING AN OPENING THEREINTO, WHICH COMPRISES ARRANGING THE BULB WITH ITS SAID OPENING OPPOSITE AND IN VACUMTIGHT COMMUNICATION WITH AN OPEN DELIVERY ENED OF A PASSAGEWAY, PRESENTING THE STRAND OF COMBUSTIBLE MATERIAL TO THE OPEN ENTRANCE END OF SUCH PASSAGEWAY, DRAWING AIR THROUGH SAID PASSAGEWAY AND OUT OF SAID BULB TO CREATE A SUCTION IN THE PASSAGEWAY SERVING TO CARRY THE STRANDS THERETHROUGH AND DISCHARGE THEN INTO SAID BULB, AND TEMPORARILY INTERRUPTING THE MOVEMENT OF SAID STRANDS BEFORE THE STRANS ARE DISCHARGED FROM SAID PASSAGEWAY AND CRUMPLING THEM THEREIN BY RELEASING THE STRANDS INTO AND IMPINGING THEM DIRECTLY AGAINST THE WALL OF AN ENLARGED CHAMBER PORTION OF SAID PASSAGEWAY. 